Chapter 7.5, Problem 15ATS

Interpretation Introduction

Interpretation:

The substrate more reactive towards ${\text{S}}_{\text{N}}\text{1}$ reaction should be identified from the given molecules.

Concept Introduction:

${\text{S}}_{\text{N}}\text{1}$Reaction: It is a nucleophilic substitution reaction in which the rate determining step depends on one reactant. First step is the formation of more stable carbocation which is followed by the attack of nucleophile. Formation of more stable carbocation and the leaving group present in the substrate plays very important role in the reactivity of ${\text{S}}_{\text{N}}\text{1}$ reaction. The increasing stability order of carbocation is as follows,

Primary carbocation < secondary carbocation < tertiary carbocation

Resonance: The delocalization of phi electrons or lone pair of electrons in p orbital within a molecule. The molecule is said to be more stable if it is resonance stabilized.

Resonance stabilization: Due to the delocalization of electrons within the molecule the overall energy becomes lower and makes that molecule more stable.

Carbocation: it is carbon ion that bears a positive charge on it.

Leaving group: it is a fragment that leaves substrate with a pair of electrons via heterolytic bond cleavage.